Field of the Invention
The present invention relates to an improvement of a differential device, particularly the differential device which distributively transmits rotational force of an input member to a pair of output shafts via a pair of side gears (output gears), the input member supporting a pinion support portion (a differential gear support portion) that supports a pinion (a differential gear) and being rotatable together with the pinion support portion, the side gears each having a tooth portion in mesh with a pinion in an outer peripheral portion of each of the side gears.
Description of the Related Art
Conventionally, such a differential device has been publicly known as described in Japanese Patent Application Laid-open No. 2008-89147, for example. The conventional differential device is configured to supply lubricant oil to sliding portions of pinions and meshing portions of the pinions and side gears via clearances between back surfaces of the side gears and a differential case and via spline-fitting portions between inner peripheries of the side gears and outer peripheries of output shafts.
However, the conventional differential device, cannot efficiently collect and reserve a large amount of lubricant oil at the meshing portions of the pinions and the side gears. For this reason, the sliding portions of the pinions and the meshing portions of the pinions and the side gears are likely to have shortage of lubricant oil supply, for example, in a case where the meshing portions are placed farther from the output shafts due to an increase in the diameter of the side gears, or under severe driving conditions such as high-speed rotation of the pinions.